Superstitious ideas are always in people's life in spite of scientific and technological advancement. Hungry Ghost Festival in China, Halloween in some western countries and Day of the Dead in Mexico are three religious festivals which are observed every year. They reveal people's idea about ghosts and spirits after death. They also include doctrines which imprison people's minds and thoughts. This thesis mainly talks about the three religious ideas about death and spirits from Buddhism, Taoism, and Christian.